Micro- and nanolander on the surface of Ryugu - Commonalities, differences and lessons learned for future microgravity exploration

Abstract

Recent Space missions to the small bodies in our Solar System have shown an increasing importance of in-situ investigations. Philae, the comet lander of the ESA Rosetta mission performed the first landing on such a small body and its results clearly enhanced the overall scientific output of the Rosetta mission. While Philae was a rather heavy (~100 kg), very complex (and comparably expensive) lander, significant scientific results can be obtained also with much smaller devices. This has not least been demonstrated by the Hayabusa2 mission, delivering the MINERVA II and MASCOT landers to the surface of (162173)Ryugu. In this paper we will compare the benefits (and drawbacks) of surface packages in the 10 kg and 10 cubic decimeter class (MASCOT-Type) with the smaller (volume ~1 cubic decimeter and mass <1 kg) MINERVA-type rovers. The MASCOT-type lander is able to carry a suite of 4-6 miniaturized high resolution scientific instruments and is equipped with attitude control/determination systems and/or orientation mechanism, In contrast stands the much smaller MINERVA-type rovers, with limited possibility to accommodate scientific instruments of high resolution, but a high robustness due to a power system based on energy storage in a capacitor, an optimized mobility. Because of its small size and low mass, there is the advantage to carry several MINERVA units on one mission.